I usually take the follower weapon, kill any boss bounty (kulle, magda, azmodan,.. on master IIRC) and then rift til 70. It can be worth a try especially in a 4man group to try and get cain/born, but I tend to level on my own, so the chance for 1 player to get the recipe is a bit lackluster.
Classwise, I feel that demon hunter and monks are strong due to their movement. Realistically tho, any class has its benefits and as long as you remember to craft new weapons at the break point levels, you should be really fine
1
Source : Someone asked about this gif on reddit